Many different types of fill valves for controlling the level of liquid in a toilet tank are known. In general such toilet fill valves operate by sensing the liquid level in the tank using a float. The toilet fill valve is mounted at a height commensurate with the height of the tank such that the float position permits flow from an exterior water supply to the interior of the tank when the water level drops below a predetermined level. Thus, toilet fill valves of this type are used to maintain the water at a selected level and to refill the tank to the selected level following a flush cycle, as well as filling the toilet bowl to a selected level.
Toilet tanks are made in many different sizes and shapes and in many different heights. If a replacement toilet fill valve is needed, it is desirable to obtain a replacement that can be quickly and securely adjusted to different lengths according to the size tank for properly positioning the float. Conventional and/or pilot toilet fill valves often include a telescoping body that is adjustable to vary the height of the float to the predetermined liquid level in the tank. More specifically, the body of the toilet fill valve can include an inner shaft that communicates with the water inlet conduit, and a riser that communicates with an outlet to the tank. Unfortunately, when the telescoping inner shaft and riser are placed in the selected position or height, improper installation, or physical bumping during the repair or maintenance of the toilet, or water pressure and vibration can cause the riser to slip out of position. The water pressure then causes the toilet fill valve to rise, which causes the water to continue running and to overflow the toilet tank.